On 2025-01-15 18:29, Mikulas Patocka wrote:
Hi
The ahash interface is slower than the shash interface for synchronous
implementations, so the patch is basically slowing down the common
case.
See the upstream commit b76ad8844234bd0d394105d7d784cd05f1bf269a for an
explanation in dm-verity.
Do you have some benchmark that shows how much does it help on s390x?
So,
that we can evaluate whether the added complexity is worth the
performance
improvement or not.
Mikulas
Just a short sniff test on my development system (s390x with 32GB RAM,
16 CPUs).
When I run a dm-integrity format command on a 16G loopback file backed
up by tempfs
I get this on a fedora40 with fresh build v6.13-rc7 kernel:
integritysetup format /dev/loop0 --integrity sha256 --sector-size 4096
...
Finished, time 00m08s, 15 GiB written, speed 1.8 GiB/s
and with the same kernel + my dm-integrity async patch:
Finished, time 00m09s, 15 GiB written, speed 1.7 GiB/s
However, I'll run some more sophisticated performance measurements
during
the weekend.
Harald Freudenberger
